JPS58184775A - Heat insulating container for superconductive magnet - Google Patents

Abstract

PURPOSE:To reduce the amount of radiation heat intruding into a helium container as well as to effectively reduce the temperature of the titled heat insulating container by a method wherein a radiation shielding cover is directly attached to the external circumference of the penetrated part of a supply pipe or an exhaust pipe. CONSTITUTION:A radiation shielding cover 4b is directly welded or silver- soldered on the outer circumference of the penetrated part of a supply tube 7. Liquid nitrogen is supplied through the supply pipe 7, and the entire helium container is cooled. As the radiation shielding cover 4b is directly attached, the entire container is cooled with excellent efficiency and the temperature falls down to that of the liquid nitrogen, thereby enabling to reduce the amount of radiation heat intruding into the helium container. Also, as the radiation shielding cover can be installed when a single unit fixing flange is assembled, the assembling to the entire heat-insulating container can be performed easily.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a heat insulating container for a superconducting i-gnet.

[Technical background of the invention and its problems]

A superconducting magnet consists of a coil made by winding a superconducting body in which superconducting wire is wrapped around a stabilizing material such as copper or aluminum, and the coil is immersed in liquid helium in a helium container and brought to an extremely low temperature below the critical temperature. keeping. The coil is in superconducting state C: Since the electrical resistance of the superconducting embroidery becomes zero, a large current can flow and a strong magnetic field can be obtained. For this reason, superconducting i-gnets are widely used in nuclear fusion and MHD power generation, and coils are also becoming more complex. By the way, the liquid helium that holds the superconducting magnets at or below the critical temperature has a very small latent heat of vaporization, and it is an important design condition to suppress the intrusion of heat into the helium container as much as possible. A radiation shield is installed between the vacuum container and the vacuum container to prevent heat intrusion due to convection.The design of this radiation shield is as follows: In this case, the radiant heat is proportional to the fourth power (2) of the temperature difference, so it is necessary to lower the temperature. The structure is equipped with a multi-layer insulation material known as a superconducting coil, and when liquid nitrogen is supplied (the temperature is lowered by two degrees). , (2) is the coil (
(1) is a helium container that houses the coil (1), (3) is liquid helium that immerses the coil (1) in the container (2), (4) is a radiation shield cooled with liquid nitrogen (5) is the container (2) and the radiation shield (4) is a vacuum container for vacuum insulation, and (6) is a support device for container (2). By the way, the supply pipe that supplies liquid nitrogen to the radiation shield and the discharge pipe that discharges it are
It is designed to penetrate empty containers and radiation shields,
Detailed diagram of this part! Figure J2 (2 shown. (5a) is a vacuum vessel (2) Fixing 7 for fixing the supply pipe and the discharge pipe
In the lunge, the supply pipe and the discharge "e" penetration part are integrated. (7) is the external liquid nitrogen supply pipe, (7a) is the internal liquid nitrogen supply pipe, (8) is the external discharge pipe, and (8a) is the internal liquid nitrogen supply pipe. is an internal discharge pipe.The fixed flange (5a) is closed at room temperature.In order to reduce the radiant heat from this part, it is common knowledge to install a radiation shield cover like (4a).However, This radiation shield cover (4a) is usually installed by bolts, and the thermal contact area with the radiation shield body is small, so the saving 1j is not reduced, and the amount of radiation heat entering the helium container is large. It had drawbacks.

[Purpose of the invention]

The purpose of the present invention is to eliminate the above-mentioned drawbacks (two things), and to provide a heat insulating container for superconducting!Gnets that can suppress the radiant heat penetration force (ttl'm).

[Summary of the invention]

In order to achieve the above object, the heat insulating container for a superconducting magnet of the present invention is installed with a radiation shield (=coolant supply pipe or discharge pipe) = radiation shield in thermal contact with the outside. Features.

[Embodiments of the invention]

The present invention will be described below with reference to an embodiment shown in the drawings. In Figure 143, the same parts as in Figure 2 are given the same reference numerals, so the explanation will be omitted.
&) is a radiation shield cover attached to the outer periphery of the supply pipe penetration (= radiation shield cover attached with thermal contact (for example, welding, silver brazing, etc.).

:: Next (Explain the two effects. Radiation shield cup (-(4b)
The outer periphery of the supply pipe purchasing part of the fixed 7 flange (5a) (2) is directly welded or silver soldered, so the entire part is efficiently lowered to the liquid nitrogen temperature by heat conduction. The temperature difference can be reduced, and the amount of radiant heat intrusion can be suppressed by billions of yen.

The above description can also be applied to the case where the radiation shield cover is attached to the supply pipe penetration part side of the fixed 7-lunge (2 (I mentioned two, but the discharge pipe penetration part - 4) is attached.

〔Effect of the invention〕

As described above, the present invention provides a radiation shield cover that is directly supplied or attached to the outer circumference of the X-portion of the exhaust pipe (=
This effectively reduces the temperature of the entire liquid nitrogen to the liquid nitrogen temperature, which has the effect of extremely suppressing radiation heat intrusion into the container. Further, since this adjustment t=t can be performed when assembling the fixed seven langes alone, there is also the effect of making the entire assembly easier.

[Brief explanation of drawings]

Figure 111 is superconductivity! Vertical section showing the entire gunnet outfit, 8
FIG. 2 is a vertical cross-sectional view showing a conventional supply pipe and discharge pipe penetrating a heat-insulating container, and FIG. 3 is a partial vertical cross-sectional view showing an embodiment of the present invention. 1... Superconducting coil, 2... Helium container 3
...Liquid helium, 4...Radiation shield 4b
...Radiation shield cover, 5...Vacuum container 5a...
・Fixed 7 lunges, 6...Support leg 7...External liquid nitrogen supply pipe, 7a...Internal liquid nitrogen supply pipe 8...
・External discharge pipe 8a...Internal discharge pipe (7317
)Representative Patent Attorney Kensuke Chika (and 1 other person) Figure 2 Figure Otsu Figure 3

Claims (1)

[Claims] A superconducting magnet, a helium container that stores liquid helium that cools the superconducting magnet, a vacuum container that holds the helium container and creates a vacuum between them, and two devices that surround the helium container. A thermal insulation reactor for superconducting magnets having a radiation shield (2) characterized in that the radiation shield is installed in thermal contact with a pipe for supplying or discharging refrigerant to the external radiation shield. Insulated container for superconducting magnets.